introduction简单

This concept has served as a central goal for curriculum developers, local school boards, business and community leaders, and policymakers ever since its introduction nearly 80 years ago.

自近80年前提出以来，这一概念一直是课程开发者、地方学校董事会、商界和社区领袖以及政策制定者的核心目标。

But exposure times were much quicker by the 1880s, and the introduction of the Box Brownie and other portable cameras meant that, though slow by today’s digital standards, the exposure was almost instantaneous.

但到了19世纪80年代，曝光时间已经快多了，而布朗尼盒式相机和其他便携式相机的问世意味着，尽管按今天的数码标准来看仍然很慢，但曝光几乎是瞬间完成的。

In most of the homeless gardens of New York City the actual cultivation of plants is unfeasible, yet even so the compositions often seem to represent attempts to call forth the spirit of plant and animal life, if only symbolically, through a clumplike arrangement of materials, an introduction of colors, small pools of water, and a frequent presence of petals or leaves as well as of stuffed animals.

在纽约市的大多数无家可归者花园里，真正种植植物是不可行的，但即便如此，这些布置似乎常常代表着一种尝试，试图通过将材料成簇排列、引入色彩、设置小水池以及频繁摆放花瓣、树叶和毛绒动物等方式，唤起动植物的生命精神，哪怕只是象征性的。

introduction

介绍；引入